Clutch Help

[slonnee1]

:angry
Hey guys, looking for some suggestions here.

Recently got my Cat-eye pocket bike and it has a less then desireable take off. I mean when i sit down on it and give it full throttle, I barely move. Checked the carb adjustments and got it to where there is a little take off. I am assuming that my clutch is the root of this evil. I Have since remove the cover and exposed the clutch. The one installed is a dual shoe with a single spring in the middle. I roughed up the clutch pads and cleaned and degreased when the pads adhere to the clutch housing and I got a little better performance. Is there anything else I can try shourt of roughing up the housing so that the pads have something other then a completely smooth surface to try to adhere to? My neighbors have a pair of them and they seem to just haul ass.
:thud

TIA
Scott

[Backwoodz]

Scott the problem is not to little friction.....but too much friction at below the optimal hp of the engine. Try drilling out the shoes. lighten them up so they will not engage until the rpm level is higher. Also check to see if the shoes you have are a steel or aluminum. The aluminum shoes will naturally be lighter and engage at a higher rpm....so I prefer them. They also make heavier springs to make this setup infinate. The performance this brings all depends on many things about the bike and engine setup.....either being stock or heavily modded.

[Straydawg63]

You might check the chain it maybe to tight only 1/2 inch of play in it

[Straydawg63]

If you lighten up the clutch shoes wouldnt it make them engage at a lower rpms.Wouldnt they engage sooner being lighter or I'm I backwards (spin me back around) Backwoodz

[Backwoodz]

If you lighten up the clutch shoes wouldnt it make them engage at a lower rpms.Wouldnt they engage sooner being lighter or I'm I backwards (spin me back around) Backwoodz
It has to do with the spring rate.....stock shoes with a heavier than stock spring lets the engine rev higher before inertia forces the shoes against the clutch bell......or a stock spring and lighter shoes do the same.
You need to know when the power band of the engine just starts coming in....this is the rpm range the shoe and clutch need to be fully engaged.
Some may call this is when you are in the PIPE.

[Scott H]

Think of it like this. If you tie a baseball to a string and sling it, the baseball will extend to the end of the string with you spinning it slower, due to the weight of the ball. Now substitute a ping-pong ball for the baseball, you will have to really sling the string around to get it to extend fully.

With the Polini bikes, we can change spring rates, preload, clutch material, number of shoes and the weight of the backing plate. How about that for variables!!

On another note, we should be getting in some fully adjustable two shoe clutches for the Cags. Sorry 49cc engine guys, nothing yet.

[Straydawg63]

Thanks now it makes more since . can they be made heavyer

[Scott H]

Yes you can make the sock shoes heavier. You can drill out a portion of the shoe, tap it and insert a STEEL set-screw (be sure to loctite it, use aluminum safe loc-tite). Now, this addition of weight is minimal but remember you are dealing with inertial forces and such so a little does have an effect.

Like stated above though, if your shoes are steel, this sill not help.

One thing we do to make our bikes run better is in the carb. Adjustment here is crucial. Also the stock filter is horrible and retrictive. And just for kicks, what is your fuel to oil ratio?

[Straydawg63]

So is it better to make the clutch engage at a lower rpm or higher rpm. So for a sooner engagement a heavyer shoe and a later engagement lighter shoe. Does it have to do with low end and high end witch way you go with it.

[Scott H]

On the 49cc engine bikes, I am not really sure what works the best.

On the Polini engined bikes we set the clutch to engauge around the 8000-8200 rpm mark.

I am not sure of the redline of the 49cc bike or where they really build power, you need to know this to get the best setting. One thing that really holds these engines back is the pipe, or lack of one. For a two stroke to make POWER it needs an expansion chamber on the exhaust pipe, it creates a pulse that evacuates the combustion chamber and causes it to fill to capacity. These bikes are coming with just a straight pipe.

We carry pipes for the x1 and the x2 call us for info. Or e-mail me harp4002@bellsouth.net.

[slonnee1]

Your Not gonna believe this. I found the root of my problem. After stripping the clutch back out and finding the usual trace remails of the cluth "Trying to work" i looked elsewhere. The pads were not polished and everything seemed in working order. For giggles I port polished my intake and opened it up. Nothing noticable. So I was putting everythign back together on the bike. I decided that a neighbor pissed me off so i left the exhaust off. And Oddly enough I took off like a bat out of hell. I was like WTF. Put pipe back on. No power. I bust out my dremel and Cut the Pipe at the weld point where it meets the Baffles. Sure enough Found the problem. The 1" pipe has a 1/8" openeing cause of some drunked ass backwards chineese welder almost welded tyhe exhaust totally closed. SO for now I am running a streight pipe. I had to open the hole where the Pipe meets the engine cause it was not opened all the way. Sure enough now I am takin off and out performing my friends bikes probably due to my port polishing and opening up the Intake and exhaust port some. Thanks for all the advise guys. U might add this to your books to look for for similar issues.